As i believe it the origionator is the sita address of the handling company of the departure station and the address is the sita address of the destination handling company.
I really don't know why that is on a manual loadsheet. I'm sure someone will tell me, but i've got a feeling its a relic left over from before computers were used to do loadsheets so that the person transmitting the LDM knew where to send the message.
Please correct me if i'm wrong.